Thread-controlling mechanism for sewing-machines.



G. W. NELSON. THREAD CONTROLLING MECHANISM FOR SEWING MACHINES; APPllcATmN man Nov. l2. 191s.

11240,@68. 1 111Q111G1sep1-2a1911 Y attain/m3 QN GQ W. NELSON. THREAD CONTROLLING MECHANISM FOR SEWING MAC HINES.

APPLICATION FILED NOV. I2, 1913.

Patented Sept. 25, 1917.

Mmes.

4 SHEETS-SHEET 2.

G. W. NELSON. THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED NOV. I2. 1913- Pateuted Sept. 25, 1917.

4 SHEETS-SHEET 3.

G. W. NELSON. THREAD- CONTROLLING MECHANISM FOR SEWING MACHINES.

I APPLICATION FILED NOV- I2, 1913. Lm.,

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non enanas narrar narnia.

GEORGE W. NELSON, F CLEVELAND, OHIO, ASSIGNOR TO THE STANDARD SEWING MACHINE COMPANY, 0]?Y CLEVELAND, OHIO, A CORPORATION OF OHIO.

THREAD-CONTROLLINGIVIECHANISM FOR SEWING-MACHINES.

Application led November 12, 1913.

i. To all whom t may concern:

' is to provide an improved pull-ofi mechanism of the general type disclosed in Patent No.7805,870, granted November 28, 1905.

The invention constituting the subjectmatter of the present application is distinguished from that of the aforesaid patent in various respects. One of the principal features vof difference is that the pull-oif proper in the present invention has a variable movement in the general direction of pull-oit instead of the fixed range of movement of the pull-off device of said patent. In addition to this the pull-off of the present case is one that preferably has a variable movement in a single path, to wit, the path of pull-olf, the extent of its movement in this path depending upon the amount of thread it is desired to draw from the source of supply. This variable movement is best obtained by the conjoint action of controlling means for determining the range of movement of the pull-olf device and of operating means for moving said device in its pull-oif path a distance determined by the action of such controlling means. This controlling means is also governed in a sewing machine of the button-hole type, in which there is a shifting movement for locating the work properly with respect to two different sets of stitches to be made, by the action of the work-holder-shifting mechanism in a manner similar to that of the aforesaid patent.

Another important feature of the present invention is the provision of a bobbin-'holder adapted to be turned to permit an additional length of thread to be drawn from the bobbin carried by it, and suitable means cooperating with said bobbin-holder for positively turning the same to assure the delivery of such additional length of bobbinthread.

@ther features of the invention not here- Speccation of Letters Patent.

Patented Sept. 25,1917. serial No. 800,495.

inbefore referred to will be hereinafter described and claimed and are illustrated in the accompanying drawings, in which- Figure 1 is an under-side View of a button-hole sewing machine embodying pull-off mechanism constructed'in accordance with my present invention;

Fig. 2 is an enlarged, vertical, transverse section of the same, the section being taken in line 2 2, Fig. 1, looking in the direction of the arrow.

Fig. 3 is an enlarged, vertical, longitudinal section of a portion of the same, the section being taken substantially in line ewa, Fig. a; c

'Figt 4 is a vertical transverse view of the machine, the section being taken in line Lil-a, Fig. 1;

Fig. 5 is a transverse section and front elevation, taken in a line passing through the needle opening in the bed-plate, of the pull-olf mechanism, the same being shown in its position of maximum throw;

Fig. 6 is a similar view, showing said pull-Gif mechanism in its position of minimum throw;

Figs. 7 and 8 are views of goods containing a button-hole and illustrate the manner in which stitches are formed by the pull-ott device, and

Fig. 9 is a detail illustrating in front elevation a throw-out device which will be hereinafter described.

Similar reference characters designate like parts in all the figures of the drawings.

My improved pull-off mechanism may be embodied in any suitable type of sewing machine, but is preferably employed in connection with a button-hole sewing machine,

' which may be a machine such as that illustrated in my prior application, Serial No. 779,984, filed July 19, 1918. The machine here illustrated is one substantially identical with that of my aforesaid application, to which reference may be made for further description of such parts as are shown herein but are not connected directly with the operation of the pull-ohQ mechanism. The machine shown comprises, among other things, a bed-plate 10, which carries in this case all of the operating parts. At the front end of said bed-plate is the needle-plate 11, having therein the usual needle opening 12 to receive the needle n.

The work is clamped as usual, in a suitable 'work-clamp, w, and this work-clamp is adapted to be shifted crosswise of the machine by suitable work-holder-shifting mechanism. lt will also have the usual longitudinal step-by-step movements to make successive stitches in each row of button-hole stitching. All of these parts are or may be the saine as those described in myl aforesaid application. l

'l'he pulloff mechanism is one suitable for the purpose of drawing olf an additional amount of thread wherever this is necessary or desirable, and it is preferably one in which the additional thread is drawn off from the bobbin for the purpose, of making button-holes w`th a properly positioned purl. The movement of the pull-olf device may be any suitable for the purpose of accomplishing the desired result, provided it isa variable one in the general direction of the pull-off path, the extent of such movement depending upon the amount of additional thread to be pulled off, if any. l-lere a pull-off device is employed, such as indicated at p.

This pull-off device is of the same general type as that disclosed in the aforesaid Patent #805,870, granted November 23, 1905,`that is to say, it is a pull-o operative at every alternate stitch for the purpose of locating the purl at the inner edge of the.

button-hole, to do which it is necessary that thepullfolf action take place on every outeredge stitch of the two rows of button-hole stitches at the opposite edges of the buttonholes. 1n order to do this it is necessary to reverse `the timing of the pull-off upon the shifting of the work-clamp for presenting the opposite edge of the button-hole to the stitching mechanism. This reversal of the timing relation of phase of the pull-off is controlled, as before indicated, from the shifting` mechanism which includes the main cross-slide 62. Y

T he connections from this main cross-slide 02 to the lower-thread pull-olf may be any suitable for the purpose. Here a depending bracket, lf2", is secured to the under slide of the bed-plate of the machine and has, at its upper and lower endsA respectively, vertical bearings for a rock-shaft, 127, cairying at its upper and lower ends respectivelytwo rock-arms. 123 and 129, the upper of which is. short forked rocker and cooperates with a pin, 130, secured to the under side of the shifting-bar 99, which is pivotally connected to an extension -110 ofthe main cross-slide 62,

so that said shifting-bar and cross-slide will are intended to work. These springs are separated froml each other by the opposite sides ofthe bored ear (through which the lreduced portion of the rod 131 passes) of a cate longitudinally of 'its axis and with itV the connected rock-arm 13G,V which has a wide forked end adapted 'to span a rearwardly projecting hub, 140, extending from a large spur-gear, 141, mountedtoturn onv a stud, 142, secured. tothe bracket 139. rllhis* h ub 140 is extended sufficiently far to provide room for central `neutral space or rounded hub portion with which the forked rock-arm 13G may cooperate, and also for a j pair of substantially triangular cams dis posed oppositely to each other and located at opposite sides of such neutral or circular portion of the hub. These kcams are indi cated at 143 and 144 respectively.

The construction of the partsiso faridescribed is such that in the making of a button-hole during the stitching rof the first rowA of regular button-hole stitches the forked rock-ar1n 136 will. coperate with the rear triangular cani 144 and will remain upon it and be rocked back and forth by it intermittently once for each two rotations ofl the looper-shaft 145. The rocking motion of the arm 136 will, of course, be transmitted to its rock-shaft 137 (then in its extreme rear-A ward position) and by it to a forward rockarin, 146, slotted at its free end to receive the rear end of a pin, V147, carried by' a rocking link, 148, pivoted at its left-hand end to the lower end of the pivoted lower-thread pull-off y?, the pivot of which is indicated at 151. At its right-hand end the link 14S has pivoted thereto a block, 148', movable in an arc-shaped slotA 153 in a rock-arm,152, secured to a long rock-shaft, 74, operated by an eccentric-rod, 23, from the main upper d-riveshaft 2l. By these connections the pull-oft' will be operated in a manner controlled by the conjoint action of the two rock-shafts 137 and 74. Thus, when the block 148 is near the lower end of the slot 153 in the work-arm 152 as shown in Fig. 5, it hasits maximum movement as Vimparted'thereto by the rock-arm 152, because it is then at vits maximum distance from the axis of the shaft 74, and the connected pull-off device p has a correspondingly great arc of oscilla'- tion which is imparted to the bobbin-case to cause a corresponding movement thereof and the drawing olf of the maximum amount of additional thread from the bobbin. When, lioweifen'theblock 148 is near the upper ingly short, it being in the illustration in Fig. 6 only sufficient to draw ofi' a slight additional amount of thread from the bobbin. At each stroke of the needle the block 148 will be shifted to one or the other of the positions shown in Figs. 5 and 6, it being4 shifted first to one and then to the other alternately in order that a considerable additional amount of thread may be supplied at each alternate stitch to provide for the proper formation and location of the purl.

Whether the forked rock-arm 136 is swung back and forth in one path by the cam 144 for one row of button-hole stitches, or is swung back and forth in another pathby the cam 143 for the opposite row of stitches depends upon the longitudinal position of the rock-arm 137, which in turn is dependent upon the action of the rod 131 and the movement of the shifting-bar 99. The movements of this shifting-bar are preferably derived, as in my aforesaid application, from a cam carried by and encircling the axis of a rotary member, 18, which constitutes in this case, as in the former, the main rotary controller' for governing most ofthe movements of the various mechanisms of the sewing machine. The cam carried by the rotary controller 18 is shown as a camgroove having four main parts, indicated at 106, 107, 10S and 109, and these sections of the cam correspond respectively to the first row of short or regular stitches, to the long or barring stitches at the end of the first row of regular stitches to the second row of short regular stitches and to the seoond row of long or barring stitches which are made to complete a button-hole; `lllhich set of stitches will be made at a given time will depend upon the position to which the shifting-bar 99 is moved'by one or another of said four sections of the cam-groove, which in turn will depend upon which section of said cam-groove is in engagement with the pin 104 secured to said shiftingbar and operatively connecting it with said cam. As said shifting-bar is rocked in one direction or the other by the walls of this cani-groove the connections to the forked rock-arm 136 will be correspondingly actuated as before described.

The rock-arm 136 remains upon the cam 144 throughout the making of the first row of regular button-hole stitches; and throughout the making of the first set of long or barring stitches at the rearend of thebutton-hole, said rock-arm 137, which is gradually shifted forward during the making of said barring stitches, leaves the cam 144 and travels upon the neutral or circular portion 140 of the hub, against which it is moved by the action of a spring 155 which normally turns the rock-shaft 137 to the left. Immediately thereafter, on the shifting of the main cross-slide 62 into position for forming the second row of button-hole stitches, the mechanism controlling the longitudinal movement of the rock-shaft 137 is operated and shifts the rock-arm 136 quickly on to the opposite triangular cam 143, the rockshaft 137 with its arm 146 moving forward at this time. This action results in reversing the timing relation of the pull-o action for thelower thread to assure the formation of the purl at the inner edge of the succeeding row of short button-hole stitches. In this shifted position of the rock-arm 130 the spring 134 is put under tension and serves to hold the parts just described in their forward position, while when in the opposite position the tension on the spring 134 is released and tension put upon the spring 133 to hold said parts in their rearward position, a'. e. tension is put upon one spring and released from the other in one condition of the parts and is put upon the second spring and released from the first in the opposite condition of the parts.

The spur-gear 141 which controls the movements of the triangular cams and forked rockarm ust described is driven, in this case, from the looper-shaft 145 by a spur-pinion, 156, in constant mesh therewith. Said loopershaft in turn is driven from the main upper drive-shaft through sprocket-wheel and chain connections, indicated at 157, 158, and 159. The lower sprocket-wheel 159 is carried near the extreme rear end of a short shaft, 160, journaled in the lower rear main bearing, 161, and carrying at its forward end a slotted rock-arm, 162, in the slot of which works a crank-pin 163, carried by a crank-arm, 164, secured to said looper-shafl', which shaft has its axis at some distance below the main lower driife-shaft 160. rlhis construction of course is for the purpose of obtaining the desired variable rotary movement of the looper-shaft and hence of the looper itself, as will be obvious.

An important feature of the invention is that the necessary additional amount of bobbin-thread is not only drawn off positively by the action of the pull-off device 7J but is drawn olf by the positive turning of the bobbin-holder by said pull-ofi. This bobbin-holder may be of any suitable construction f'or the purpose and is designated generally by 225. lt is adapted to carry the bobbin and its thread in a well-known manner, and has on the outside thereof a projecting element, such as 226, disposed in the path of the pull-olf p and preferably between the two ends 227 and 228, of the forked arm here illustrated as the specific type of pull-o device used. It will be clear `by reference to Figs. 5 and 6, that the actuating elements 227 and 228 of the pullolf device will positively turn the actuated element 226 of the bobbin-holder in the one direction or the other as the pull-off p swings back and forth, and it will also be clear that the extent of the turning movement of thebobbin-holder will be dependent upon that of said pull-ofi.

In Figs. 7 and S I have illustrated how the pull-oli device acts upon the bobbinthread 2 to draw off a sufficient quantity of thread, which may be much or little, to locate the purl in any one of various desired positions, away from the edge of the button hole, as shown at 5, in Fig. 8, or at the edge of said button-hole, as shown at 6 in Fig.

7. Fig. S illustrates how the same quantity of thread isdrawn olf from thebobbin at each stitch and how the under thread is drawn vby the needle-thread 'above the goods at the inner edge of the buttoirliole, as shown at 3, and how at the next stitch at the outer edge of the row said under thread is again drawn above the goods, as shown at 4, in said figure; while Fig. 7 illustrates the operation that takes place when the pull-oli acts upon the bobbin-thread only at each alternate stitch when a sufficient quantity of additional thread is drawn from the bobbin, as shown at 7, to permit the thread pulled 0H to be drawn over to the inner edge of the button-hole and hence form the purl at said inner edge.

It will of course be evident that in this machine either a whip stitch or a purl stitch may be made. In makingy the plain or whip stitch the pull-oit device for the lower thread is rendered ineffective inl some snitable manner, as for example, by dropping a throw-out device in the form of a latch, 221, into a notch, 221', in the controlling rockshaft 137 for the lower thread, which action results in locking said rock-shaft against longitudinal movement with the rock-arm on the central or neutral portion of the controlling device, that is, on the neutral p0rtion between the cams 143 and 144, in which position said rock-arm 136 is ineffective to swing the block 148, the movement of which controls the amount of lowerthread pulled oill from the bobbin.

What I claim is v l. In a sewing machine, the combination with stitch-forming mechanism, of a bobbinholder, a bobbin-thread pull-oli" coperative with said bobbin-holder to turn the same and having a variable action in the general direction of the pull-off path, andV means for operating said pull-oit in said direction to act lupon the bobbin-thread in a different manner for different stitches.

2. In a sewing machine, the combination with, stitch-forming mechanism, of a bobbinholder, a bobbin-thread pull-ofi' coperative with said bobbin-holder to turn thesame andhaving a variable action inthe general holder, a bobbin-thread *pull-off coperative with said bobbin-holder to turn the same and being constantly maintained in its pullofi path, and means for operating said pulloff to act upon the bobbin-thread during the formationof certain predetermined stitches and to maintain said pull-olf in inoperative relation with said bobbin-threadduring the formation of certain other predetermined stitches.

4. In a sewing machine, the combination with work-holder-shifting mechanism, of a bobbin-holder, a thread-pul-l-off cooperative with said bobbin-holder to turnA the same and having a variable actionin the general direction of the pull-off path, and means controlled by said work-holder-shifting mechanism for yoperating said pull-off kin said direction to act upon the thread in a different manner for different stitches.

5. In a sewing machine, the combination with stitclrforming mechanism, of a bobbinholder, and a bobbin-thread pull-od coperative with said bobbin-holder to turn the same, automatic means for varying the range of throw of said pull-od, and means for actuating said pull-od the determined distance in its pull-ott path.

6. In a sewing machine, the combination withstitch-forming mechanism, of a bobbinholder, and a bobbin-thread pull-.off comprising an actuated element carried by the bob*- bin-holder and an automatic actuating element supported independently of the bobbin-holder and cooperative with said actuated element to turn said bobbin-holder different distances at diderent stitches.

7. In a sewing machine, the combination with stitch-forming mechanism, of a bobbinholdcr having'an actuated member, a pivoted bobbin-thread pull-ofi" supported` independently of the bobbiirholder and cooperative with said actuated member to turn said bob bin-holder, and means vfor operatingsaid pull-oliil in determined'timing.different distances at different stitches.

8. In a. sewing machine, the combination with stitch-forming mechanism, of a bobbin-v holder havingan actuated member, a pivoted forked bobbinthread pull-olf supported independently of the bobbiirholder and coperative with said actuated member to turn with stitch forming mechanism, of a bobbinholder, and a hobbin-thread pull-off comprising an actuated element carried by the hobbin-holder and an automatic actuating element supported independently of the hobbin-holder and cooperative with said actuated element to turn said hobbin-holder and iaviiig a Variable throw.

10. ln a sewing machine, the combination With stitch-t'orining` mechanism, of a pivoted thread-pull-otl, an actuating rocker for imparting a swinging movement to said pullofi, an operative connection from the pullo to said rocker, and means shifting said connection at its rocker-engaging end in a direction toward and from the rocker axis at alternate stitches.

" stitches.

12. In a sewing machine, the combination with stitch-forming mechanism, of a thread pull-off, an actuating rocker havinga fixed throw, a block slidably mounted on said rocker, a link pivotally connecting the pullolt' wit-li said block, and means shifting` said block toward and from the rocker'axis at predetermined stitches.

13. ln a sewing machine, the combination with stitc-.lrforming mechanism, of a threadpull-ott', an actuating rocker, a block slidably mounted on said rocker, an operative connection from the pull-off to said block, and means shifting said block toward and from the rocker axis at alternate stitches.

111. ln a sewing machine, the combination with stitch-forming mechanism, of a threadpull-0H, an actuating rocker hai/'ing a xed throw, a block slidahly7 mounted on said rocker, a link pii-'otally connecting the pullottl With said block, and means shifting` said block toward and from the rocker axis at alternate stitches.

Signed at Cleveland, in the county of Cuyahoga, and State of Ohio, this 8th day of November A. D. 1913.

GEORGE Vif. NELSON.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

